


Deathly Hearts

by Fanfic_Gorgeous



Category: Shall We Date?: Obey Me!
Genre: AU?, Angst, F/M, Fluff, Jealousy, Mentions of PTSD, Multi, Past Alcohol Abuse/Alcoholism, Past Child Abuse, Platonic Cuddling, Platonic Female/Male Relationships, Platonic Kissing, Possessive Behavior, Reapers, Romance, Sexual Content, Sexual Tension, Smoking, Violence
Language: English
Status: In-Progress
Published: 2020-12-14
Updated: 2021-01-20
Packaged: 2021-03-10 22:55:37
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,624
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28065081
Author URL: https://archiveofourown.org/users/Fanfic_Gorgeous/pseuds/Fanfic_Gorgeous
Summary: Killian is a reaper.No, the kind that lives a gross cave with candles marking the life of a soul! That is a small percentage of her kind.The prestigious war hero in her realm, Killian finds herself as the unofficial babysitter of seven demon brothers after sent to the Devildom as an exchange student by her father.Follow Killian as she ventures through a chaotic year of angels, demons, while protecting her human counteract from hungry demons as she navigates romance, drama, her past, and suppressing the urges to punch a certain eldest brother in the mouth.
Relationships: Asmodeus (Shall We Date?: Obey Me!)/Original Female Character(s), Barbatos (Shall We Date?: Obey Me!)/Original Female Character(s), Beelzebub/Belphegor (Shall We Date?: Obey Me!)/Original Female Character(s), Belphegor (Shall We Date?: Obey Me!)/Original Female Character(s), Diavolo (Shall We Date?: Obey Me!)/Original Female Character(s), Leviathan (Shall We Date?: Obey Me!)/Original Female Character(s), Lucifer (Shall We Date?: Obey Me!)/Original Female Character(s), Luke (Shall We Date?: Obey Me!) & Reader, Mammon (Shall We Date?: Obey Me!)/Original Female Character(s), Original Female Character(s) & Original Female Character(s), Original Female Character(s) & Original Male Character(s), Satan (Shall We Date?: Obey Me!)/Original Female Character(s), Simeon (Shall We Date?: Obey Me!)/Original Female Character(s), Solomon (Shall We Date?: Obey Me!)/Original Character(s)
Comments: 2
Kudos: 13





	1. Prologue

**Author's Note:**

> Hi!
> 
> This is my first Obey Me fic, so I do appreciate constructive criticism! If you like it, plz leave a kudos!
> 
> I hope you enjoy!

Between the four realms, the Reapscape is most unknown of all. 

The home of the reapers, magical beings who collect the souls of recently deceased. There is little knowledge of the Reapscape as it was the intent of the realm ruler. After the Great Celestial War, the Grim Reaper, ruler of the Reapscape, placed an unbreakable seal on the realm, preventing angels, demons, and the living from entering without their direct consent. 

For millennia, the Reapscape remained isolated from the other realms. However, reapers still travel to and from the human realm often to collect souls. Reapers still had minimal contact with outsiders, often avoidant of angels and demons while collecting. Exiled reapers often resided in the Devildom or the human realm, often called the Ravished by their kin. They committed crimes against their own kind. Yet, their horrible nature has become the basis of the other realms’ perspective of reapers.

The reapers were gluttonous creatures to angels and demons, residing in dampened caves, waiting for a candle to die out before harvesting a soul to devour. With these falsehoods polluted the other realms, the Reapscape still remained isolated.

Until a letter from the Devildom arrived for the Grim Reaper.

The author introduced himself as Diavolo, the crown prince of the Devildom. The demon prince asked for an audience with the Grim Reaper, requesting permission to enter the blocked realm. The prince never once stated his reasons for visiting. For unknown reasons, the Grim Reaper granted his request, welcoming the demon prince into his palace. 

The two had many pleasant conversations throughout the demon prince’s month-long stay. The prince was courteous and polite, often awed by the beauty and oddities of the Reapscape. On the final night, the demon prince revealed the purpose of his visit to the Grim Reaper. Diavolo expressed a dream of unity between the four realms, where angels, demons, reapers, and humans could co-exist without fear. He told the curious ruler about a student exchange program at his academy, asking for his participation in selecting two students to enroll in this program. 

Surprisingly, the Grim Reaper didn’t laugh at the foolish-sounding dream; he merely accepted the demon prince’s request. Then, the demon prince asked if he would add a condition to their agreement. Curious, the ruler agreed to hear. 

With a wide grin, Diavolo declared his condition, “Your Excellency, I want your daughter to be the first reaper student to walk the halls of my academy.”


	2. Arrival

**Notes for the Chapter:**

> Hi! 
> 
> I finally found the energy to edit the first chapter! I wanted to explain a few things about Mattie (The human; the usual MC of the game), Killian (my reaper mc of sorts) and the story. 
> 
> 1\. Mattie identifies as genderqueer; The pronouns of Mattie are They/Them, just like in the game. (Killian's pronouns are She/Her as she identities as cisgender). 
> 
> 2\. This story will follow the overall plot line relatively close, it will kinda diverges from the original story in a few major events. there is also some side plot and funny (sometimes spicy~) filler chapters. 
> 
> 3\. Mattie will not be the one romancing the boys, Killian is the romantic interest. Mattie will develop deep platonic relationships with the boys, I'm still deciding upon Mattie's sexual preference (possibly gray-ace?) 
> 
> 4\. Since this is somewhat an AU; there will be chapters outside of the realm of the devildom, focusing on Killian's backstory and the Reapscape. 
> 
> 5\. Last but not least, there will be some dark topics explored (mostly involving Killian's past) that I hadn't tagged yet. I will put trigger warning in the beginning notes of those chapters. If wanted, I can put line break around the sensitive materials. 
> 
> Regardless, Please enjoy!

Killian didn’t know what to expect of the Devildom. Her knowledge of the realm was solely based on books and tales of her father’s younger days as he had been good allies with the Demon Lord. Diavolo had spoken about his home realm during his stay, now Killian regretted not asking further questions. Especially after she agreed to become a lab rat to the demon prince’s social experiment, his decree caused an uproar in her father’s court, shouting of royal advisers and loud gossiping among members of the reapscape’s nobility flooded the otherwise organized hall. 

Among the chaos, her father sat on his throne, quietly observing the unleashed mayhem as she stared, shocked at Diavolo. The demon prince stood unflappable, the midst of the yelling and arguing, his eyes trained on her. The golden hues pierced her icy eyes, and his radiant smile remained unbreakable as a few irate advisors began to hurl thinly-veiled insults, stabbing at the demon prince’s character and integrity. Killian knew Diavolo didn’t care; the advisors could throw stones at him like a humorless jester telling bad jokes, he would still stand tall and proud as he awaited her answer. 

Killian felt her father’s steely gaze latch onto her; he also awaited her answer. Usually, Killian felt graceful that her father always let her make her own decisions, but at that moment, she wished he had said something. Anything. 

As she expected, her father remained silent as he stood up, his towering frame immediately silencing the hall. Her father turned to her, his dark eyes joining a hundred pairs piercing her; All awaiting an answer. 

She didn’t know why she said yes. Diavolo’s dream was one that Killian shared; she also envisioned unity among the realms. But a dream is just a dream, a wild fantasy that will never come true. Diavolo’s idea was too outlandish; she couldn’t fathom reapers that won’t be a Ravished or an outcast in the Devildom, let alone a human. 

Demons would tear a human to pieces the moment they stepped foot in the realm of the demons. Killian has witnessed many aftermaths of demons’ ravenous hunger for humans, to confirm that fact. But Diavolo wouldn’t listen even if she begged him on her knees as it wasn’t her place, much to her dismay. She was only a guest at the Devildom. Her only goal is to participate as a student for a year and report back to her father about her own opinion on the program. 

Nothing more and nothing less. 

~Line Break~

“Welcome to the Devildom, Killian!” 

A smile graced her face, her eyes landing on Diavolo as the mist of his transport spell vanished. Standing in the center of a raised judge panel, his already large frame looked gigantic as the demon prince peered down at the reaper. She recognized his signature red ankle-length coat, the crimson of his clothes heavily contradicting the large assembly hall’s violet and black scheme. Diavolo’s face brightens as he takes in her form, his gold eyes practically glow with excitement in the dimness. 

“I’m honored to be here. I was starting to think that you forgot about me.” Her mask’s lips curled into a grin as the magic-infused in the porcelain mirrors her facial expressions. Killian didn’t usually wear a mask; her arrival to the Devildom coincided with the Melachonia festival in her home realm. Not wanting to break tradition, she decided to partake in the porcelain mask tradition during those significant months, though its appearance made her stick out like a sore thumb. 

Diavolo chuckled at her tease, “Killian, you are someone who isn’t easily forgotten,” His gold eyes twinkled gleefully. “I do apologize for the delay. We had some difficulties with bringing Mattie to RAD.” Diavolo’s gaze shifted past the reaper, who turned to follow his stare. 

A small distance behind her stood a human; their aura confirmed it. The person flinched when they noticed her glance, their eyes widening at the sight of her mask. They stood shorter than her, about chin-height to her. Killian noted they were cute, admiring the human’s olive skin and dyed teal hair, styled into a chin-length choppy bob, framing their round face and button nose. 

Killian smiled, forcing back a giggle as the human gasped at her mask’s movement. “Hello there, I’m Killian. Who are you?” Keeping her voice smooth and calm, not to frighten the human further. “I-I’m Mattie. Mattie Carson.” Their doe-like eyes were glued to the mask’s mouth, watching in awe as the thin line moved and took shape, mirroring every word the reaper spoke.  
Their cheeks flushed as a giggle escaped Killian, immediately averting their glance in embarrassment. 

“I’m glad the two of you are getting along well,” Diavolo smiled, observing the duo’s interaction happily. The demon prince seemed elated by the newest students’ friendly exchange; joy practically oozed from every pore. “Killian here is a good friend of mine. Treat her kindly, and she will do the same.” 

Friends? Diavolo’s comment surprised her. She never thought he would consider her a friend. During his stay, Killian always made an effort to be friendly with the demon prince as their first meeting didn’t leave the best first impression whenever she bumped into the demon in the hallways and at banquets. Their chats were amiable but not enough to warrant status as the demon prince’s good friend.

Nevertheless, Killian took the opportunity to joke, “Aw, you’re going to make me blush~” Amused at the faint flush on Diavolo’s face as he laughed, also amused by their banter. A loud cough drew Killian’s eyes to the demon standing next to Diavolo, wearing a black version of the prince’s uniform. The demon was almost as tall as Diavolo, incredibly handsome with flawless porcelain skin and silky black hair. Even from the far distance, Killian noticed the crimson gradient in the demon’s otherwise piercing grey eyes. Those scrutinizing eyes glared disapprovingly, unamused of her playful attitude. 

Killian grinned, winking at the scowling demon. She watched gleefully as his glare deepened. Obviously, the demon didn’t like her, not like she gave a shit about his feelings. If the demon was judging her already without getting to know her, Killian didn’t want to waste her energy on trying to be liked by some demon with an apparent stick up his ass. 

“I apologize. We got off-topic.” Diavolo’s laughter subsided; he gesticulated around the hall as if performing a magic trick. “I should explain where we are. This is the Royal Academy of Diavolo, though we just call it RAD. You’re standing inside of the assembly hall, the very heart of RAD. This is where we officers of the student council hold our meetings and conduct our business.” Killian glanced around the impressive room, and she noticed a few empty seats among the ones occupied by a few disinterested demons. 

“I’m the president of said council.” Diavolo stated proudly as if demons were fearless enough to run against him for the seat. She counted the number of seats, growing more curious. There were eight seats, including Diavolo; three seats were vacated. Why isn’t the whole council here? Won’t it have been more proper to have the full council present for the new students’ arrivals? 

“Why are we here?” Mattie asked firmly, some of the shock and fear melting from their body. Killian felt slightly happy at the human’s growing confidence; the human will need that moxie if they want to survive the Devildom for the next year. Although it won’t prevent them from being eaten, it was at least progress. 

“I will explain everything to you.” The black-haired demon spoke, ascending down the center stairs of the panel towards the two. Killian willed herself not to step forward in front of Mattie protectively; her posture grew rigid and alert. Her thumb fiddled with the ring on her right index finger, containing her scythe. The smile on Diavolo’s face eased her a bit; she still won’t hesitate to attack if the demon tried anything funny. 

“Mattie. Killian. This is Lucifer. He is a demon and the Avatar of Pride.” Killian studied the black-haired demon with mild interest, so this is Lucifer? Diavolo spoke a lot of his dear friend during his stay in the Reapscape. From his descriptions of the demon, Killian honestly thought Lucifer was an old grumpy cat whom Diavolo grew fond of. Finally, now that she put a name with the face, she thought of him more like an arrogant peacock, domineering over ostentation of peafowls. 

“So, you’re Lucifer? Lord Diavolo spoke many praises of you to my Excellency.” Her father’s title felt odd on her tongue. She doesn’t remember the last time when she had to call him by that status as “father,” and the occasional papa was his usual title to her. But her father had requested her royal status to remain anonymous during her participation in the program; Killian needed to remember that she wasn’t the Grim Reaper’s daughter in the eyes of these demons. She was just a representative of the Reapscape handpicked by the demon prince. 

“He’s also the vice president of the student council and my right-hand man...and not just in title, I assure you.” Diavolo added. Killian disguised a sudden laugh as a mild cough fit, nearly giggling as Mattie shot her an odd look. Diavolo slightly pouted, resembling a worried puppy more than a demon prince. Lucifer’s glare intensified; oh, he knew exactly what she was thinking. Killian didn’t care if his stare melted the flesh off of her bone. The accidental double meaning was too funny not to laugh at. 

Killian let out a quick apology in between fake coughs, claiming she was okay. Reassured that the reaper wasn’t about to keel over and die, Diavolo continued to praise Lucifer. “Beyond that, he’s also my most trusted friend,” Lucifer grunted at his words, annoyance twitched at his features as his stare shifted to the prince. 

“Flattery will get you nowhere, Diavolo.” He cleared his throat; his red-grey eyes pierced the two exchange students. Mattie winced at the intensity while Killian merely stared back, unbothered by the demon’s biting gaze. Being a royal heir, she grew custom to the glares and gawking of nobles as she wasn’t introduced into palace life with open arms as a young reaper. 

With practiced grace, Lucifer placed a gloved hand to his chest, slightly bowed his head towards the duo as he spoke, “Speaking on behalf of the entire student body at this great and storied school of ours, I offer you a most heartfelt welcome.” Killian blinked; that was one of the driest greetings she has experienced. She endured stabbings more heartfelt. 

“On behalf of the students?” A faint frown appeared on the human’s face. Killian didn’t need telepathy to know Mattie found Lucifer’s welcome less than warm. Lucifer’s eyes briefly narrowed before he diverged into a monologue, “Diavolo believes that we demons should start strengthening our relationship with both the human world and the Celestial Realm. As a first step towards this goal, we’ve decided to institute an exchange program.” Killian turned him out. She already heard the program’s nature when Diavolo did his sales pitch to her father, resulting in brief mayhem occurring in the royal court. 

“You both need someone to look after you, and I think that someone should be my brother Mammon?” The name seemed familiar to Killian; where has she heard that name before? 

“Your brother?” Mattie asked curiously. 

“Yes. He’s the Avatar of Greed, and… how should I put it…?” He sighed defeatedly, rubbing the bridge of his nose as if a headache was forming. “You’ll understand soon enough.”

Reaching into a coat pocket, Lucifer retrieved two cell phones. “Here, take this device. It’s called D.D.D. It’s a lot like the cell phones of your worlds,” He plopped the phones into each of their hands; his aim missed Killian’s hand, the phone nearly slipped. Her quick reflexes easily caught the falling phone; she gave him a sharp look. If Lucifer purposefully missed, his face didn’t show its guilt as he further discusses the new cell phones. 

With an annoyed huff, Killian decided to examine the new device. Her phone case was a dark red; she lifted the phone slightly. She let out a breathy laugh as she saw the case matched the color of Diavolo’s uniform. Killian playfully winked at Diavolo, noticing the man also looking at the case in her hand. Diavolo’s smile widened; she suppressed a crackle when he winked back. 

Forcing herself to turn away as not to draw any attention, she turned it on to see the phone was already charged and unlocked. Killian quickly browsed the standard installed apps. Although it will take some time for Killian to get used to a new cell phone, everything seemed in place. She wondered if her other phone would work if she needed to call home. She knew there would be metaphorical hell to pay if she didn’t text Jules often. The reaper shuddered at the thought of being on the end of her dear friend’s notoriously short temper. That wasn’t something she wanted to deal with any time soon. 

“Now, go ahead and try calling Mammon with it.” Lucifer instructed.

**Notes for the Chapter:**

> Thank you for reading! Please leave a kudo and a comment, constructive criticism is welcomed here! 
> 
> Stay tuned for the next episode: The Great Mammon and The Third-born Brother!


End file.
